1. Field of the Invention
The present invention generally relates to computers. More specifically, the invention relates to an interface connection between a computer communications card and a transmission media line.
2. Description of the Related Art
Many computer firms recently have developed down-sized, internal communications cards for use with portable computer or other electronic equipment. These down-sized, internal communications cards now commonly embody such devices as modems, fax/modems, Local Area Network (LAN) adaptors and cellular equipment. Many of these firms, in designing such communications cards, also have embraced the Personal Computer Memory Card International Association (PCMCIA) guidelines for the physical specification and electronic architecture of the cards.
The PCMCIA guidelines define three types of cards and sockets for device support. All cards have the same length and width (roughly the size of a credit card) and each plugs into the same 68-pin connector. The guidelines further provide for cards of differing thicknesses: a Type I card of 3.3 mm; a Type II card of 5.0 mm; and a Type III card of 10.5
The PCMCIA guidelines also define corresponding types of sockets. Type I sockets support only Type I cards. Type II sockets support Type I and II cards, and Type III sockets support all three types of cards.
Designers commonly have used the Type II card guidelines in connection with modems, fax/modems and LAN adaptors. In such applications, the communications card must interface with a transmission media line, such as, for example, a telephone line or a twisted-pair cable. The electrical connectors used with such transmission media lines, however, generally exceed the thickness limits imposed on Type II PCMCIA cards. For instance, a modular telephone plug (i.e., RJ-11 connector) generally has a thickness of 8.0 to 12.0 mm which exceeds the 5.0 mm thickness limit of the Type II PCMCIA card. The Type II PCMCIA card thus cannot accommodate a socket at the exposed end of the card which is capable of receiving a modular transmission media line connector.
Many computer firms have addressed this problem by using flexible connectors or adaptors, usually connected to an end of the card that faces away from the bus interface, to connect the communications card to a connector of the transmission media line. In modem applications, these adaptors include RJ-11 sockets which receive an RJ-11 telephone line plug and a slimmer electrical connector (e.g., a card edge connector) for interconnection with a corresponding connector formed on the exposed edge of the communications card.
Such prior adaptors, however, suffer from several drawbacks. Prior adaptors require the user to externally carry the adapter from the computer. A user thus must remember to bring the adaptor with the computer, otherwise he or she could not use the communications card. Users also commonly misplace or lose such adaptors. In addition, prior adaptors commonly are bulky, which exacerbates the problems associated with externally carrying the adaptor. Prior adaptors further typically extend well beyond the periphery of the host computer which sometimes poses problems when used in tight space confinements.
Another computer firm has introduced a pop-out-type connector which is internally stored within the communications card when not in use. The connector pops out of the communication card with a touch of a finger to expose a socket for the transmission media line connector. U.S. Pat. No. 5,183,404 issued Feb. 2, 1993, and entitled "Systems For Connection Of Physical/Electrical Media Connectors To Computer Communications Cards", disclosed this type of internal connector.
Although this internal, pop-out-type, communications card connector proposes one solution to the problem of storage, it creates at least one other drawback. The retractable connector is permanently attached to the communications card for storage purposes. But when the connector becomes damaged or worn, the permanent attachment of the connector to the communications card forces the user to dispose of the entire communications card.
Such damage and wear is likely because the mechanical components of the connector and of the actuation mechanism used with the connector tend to wear and fatigue quicker than the electronics of the communications card. The adaptor, which extends outside the computer shell when used, also is more susceptible to damage than the communications card positioned within the corresponding socket. Expensive PCMCIA communications cards thus are discarded due to the failure of relatively inexpensive, but damaged or worn connectors.